The Biography Channel recently did an interview with Mae and Stephen West, children of notorious British murderers Fred and Rosemary West. They consider themselves lucky that they survived, since their sisters Anne Marie and Heather were murdered by their parents. Throughout their lives Mae and Stephen were told that if they misbehaved, they would end up under the house "like Heather." After the police raided the house, the children found out that this was not an idle threat. The body of Heather, along with several other young women who either worked for or were acquaintances of Fred and Rose, was found under the house.
Predictably, Fred and Rose were abusive parents. Fred frequently sexually assaulted his daughters, and they brought home their other sex partners, and Rose never hid the fact that she was a prostitute from the children. Both parents physically abused the children, and Anne Marie's death was likely the result of a beating gone too far. Hearing Mae and Stephen speak about their childhood, they show little emotion, but Mae frequently looks down, and both speak softly as they relive their experiences and how they wished for "normal" parents. Sex was so out in the open, they say, that they felt like they weren't allowed to be children. Add to that the horrific abuse, and it's surprising that Fred and Rose West's surviving children didn't become murderers themselves, although Fred's cousin was arrested shortly after the Wests for sexually assaulting young women.
Teresa Knorr was another sadistic parent that frequently turns up in the backgrounds of serial killers. Teresa killed her first husband and drove away at least three others with her possessive and jealous nature. After claiming self-defense in the murder of her first husband, saying he was abusive, a claim that may or may not have been true, she was found not guilty. She had several children with her many husbands, and was abusive to all of them, especially her daughters. When her daughter Susan died from a gunshot wound inflicted by Teresa, the mother ordered her two sons to help her dispose of their sister's body. Susan Knorr's body was discovered, and Teresa was charged with murder. On a TV show about Teresa, her surviving daughter wonders what kind of person she will be after having a mother like Teresa Knorr. While not all children of parents like the Wests and Teresa Knorr end up violent criminals themselves, coping with this type of trauma is never easy, as seen on the faces and heard in the voices of Mae and Stephen West.
It's rare to hear about a serial killer's children, because most of them don't have any. If they can't sustain a relationship, as most psychopathic killers can't, they usually don't get as far as having children. But the ones who do, either because they are experts at hiding their secrets from their families, or, like the Wests, have found a kindred evil spirit, inflict untold damage to their children, either physically or when the child discovers that their father (or mother) has been keeping such a horrific secret.